Lewis & Short

sēpŏsĭtĭo, ōnis, f. [sepono],

  1. I. a laying aside, setting apart, hoarding: pecuniae, Veg. Mil. 2, 20.
  2. II. A separation (postclass.): si forte qui decimam vovit decesserit ante sepositionem (for which, just before, separata), Dig. 50, 12, 2, § 2.